As an electric power converter for converting power between DC power and AC power, one including a semiconductor module with a built-in semiconductor element therein and a DC bus bar connected to the semiconductor module has been known (refer to Japanese Patent No. 5263334).
The semiconductor module includes a main body portion with the built-in semiconductor element therein and a DC terminal projecting from the main body portion.
The DC bus bar is connected to this DC terminal.
A penetrating portion penetrating in a thickness direction of the DC bus bar is formed in the DC bus bar.
The DC terminal is welded to the DC bus bar under a condition where the DC terminal is inserted into this penetrating portion, and a side surface of the penetrating portion and a principal surface of the DC terminal are in contact with each other (refer to FIG. 28).
The penetrating portion is formed in a shape in which one side thereof in a width direction that is perpendicular to both a projecting direction of the DC terminal and a thickness direction of the DC terminal is open.
However, there is a possibility that a relatively large inductance that is parasitic to the DC bus bar in the electric power converter occurs.
That is, the penetration portion of the DC bus bar is formed in the shape in which one side in the width direction is open in the electric power converter.
Therefore, no metallic material constituting the DC bus bar exist in this portion of one side in the width direction of the DC terminal, thus the DC bus bar is divided by the penetrating portion.
Therefore, a current path around the DC terminal is limited in the DC bus bar.
Therefore, the number of the current paths in the DC bus bar is small, and there is a possibility that a large parasitic inductance occurs in the DC bus bar.
Accordingly, when the semiconductor element is switched, a possibility can be considered that relatively large surge occurs due to the inductance.